Electrical questions

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Jul 4, 2011
Fort Pierce, Fl
Hello, I have a 76 FJ 40 which I have some electrical questions. They are as follows: 1- headlights/running lights- when I pull out the light switch to the first position, the headlights stay on and the running lights go off. Also, when I pull the turn signal/brights arm, the headlights go off. I think it was desired incorrectly. What is the proper wiring? Does it just sound like the light switch is incorrectly wired?

2- is it normal for the turn signal not to go off after a turn and you have to click it off manually or is there something I can do to make it work automatically?

Ed, Are you're saying the headlights and running lights are on before you pull the switch out to the first position? That's how your description reads.
Hello: no, when the switch is pushed all the way in, everything is off. When you pull it out to the 1st position, only the headlights are on. When you pull it to the second (or all the way out), the headlights and running lights are on. I am pretty sure that the first click/position should be the running or parking lights only and that the fully extended or second position should be headlights and running lights. I am also feeling that this relates to the brights problem on my turn signal. When I pull the turn signal toward me to flash my brights, the headlights turn off.

I also am trying to figure out whether the turn signals should click off automatically after your turn and if so, how can I get mine to do that?
I thin you have the running lights and headlights wired backwards at the switch. The switch just routes the 12V input. In the first position the 12V is routed to pins where the running light wires connect. In the second position the pins wired to your brightness selector (mine is on the floor).

Sounds like you need a couple wire swaps at the switch. That's first, then see if all operation works.

Has the switch been out and rewired?

For turn signal cancellation I believe there is a pin on the backside of the steering wheel that physically clicks the selector back to a neutral position, but I'm not the expert.

Post up more about the wiring issue and we'll get it sorted.

What year truck? New wiring harness?
Hello: bought the 76 fj40 about three years ago. Looks like it had been taken apart when the previous owner did v8 swap and paint job. Wiring looks original but probably put together wrong. I feel the same thing on the lighting problem I just need to know what goes where?
As far as the turn signal clicking off, should I take apart the plastic on the column and look around? Here would the pin be? Thanks, ed
I'll have to look at a 76 wiring diagram. Your switch has one wire that is the 12V input. 12V just sits there waiting for you to pull the switch. When you pull to first position a small metal contact in the switch moves with it an it makes a solid connection in the switch to another wire or wires. This sends 12V to the running lights. Pullit further and the shorting bar inside now also sends voltage out to the dimmer switch.

We just need a wiring diagram or a multi meter to figure out what is what.

It's a very simple theory of operation and it helps to get a picture in your head of what's going on.
Yes, I know it is probably a simple problem to fix, I just need to know what goes where? If you do come you with the wiring diagram I would appreciate the help or a copy. Thanks, Ed
Your '76 couldn't be much different than my '77. Underside of steering wheel has two signal cancelling pins. One for left, one for right. Positioned on the top 1/3rd of the back side of the wheel. As for the head lights--the first detent is for the parking lamps/side markers(also the interior heater/underdash lights-known as the upper and lower heater control lights, and the combination meter lights,). The second detent(full out) is for the headlights.
The headlight flasher(High beam) is activated when you pull the springloaded turn signal arm towards you. When you release, the headlights go back to low beam. Pushing the arm forward one detent activates the high beams. This is all contacted inside the turn assembly under the steering wheel. The headlight beam issue might be the contacts inside there. The assembly has a spring and ball affair that rides against a clip that has two indents in it. The spring fits up inside the turn signal handle, with the ball riding between it and the clip. My spring was bad--I replaced it with a--Parker rollerball pen spring-works good now.
here's what I did in my 76, remove the light switch, take off the knob first ( I believe its an allen head or phillips screwdriver), then take the rest of the switch off.
1. connect a test light to ground and touch the wires one by one
2. there should be only one wire with power, that is your accesory power wire, make note of which wire this is.
3. Turn the headlight switch to the first position (running lights) repeat step one, there will be two wires with power, one is the accesory wire from number 2, the other is your headlight wire, which is currently hooked up to the wrong terminal. make note of this wire.
4. Turn the headlight switch to position 3, there should be power to 3 wires, the new wire with power is your running light wire.
5. cut the headlight wire and the running light wire.
6. get two pieces of heat shrink and slide one onto each wire.
7. solder the headlight wire where the running light wire was, and visa versa
8. slide the heat shrink over the junction and apply heat.
9. re-assembly is reverse of dis assembly.
test the switch before you solder everything back together. Also, the wire coming out of the very back of the switch is the interior light wire, ignore that.

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